2010. National Geophysical Data Center. This line shapefile shows lines of equal annual change (secular variation) in the horizontal component of the total field intensity of the Earth's ... National Atlas of the United States.
Search Results
2010. National Geophysical Data Center. This shapefile shows lines of equal annual change (secular variation) in the inclination of the Earth's magnetic field, derived from the Internatio... National Atlas of the United States.
2010. National Geophysical Data Center. This line shapefile shows lines of equal annual change (secular variation) in the vertical component of the total field intensity of the Earth's ma... National Atlas of the United States.
2010. National Geophysical Data Center. This shapefile contains isodynamic lines (lines of equal total intensity of the Earth's magnetic field), derived from the International Geomagnetic... National Atlas of the United States.
2010. National Geophysical Data Center. This line shapefile shows lines of equal vertical intensity of the Earth's magnetic field, derived from the International Geomagnetic Reference Fie... National Atlas of the United States.
2006. Geological Survey (U.S.). This point shapefile portrays major dams of the United States, including Puerto Rico and the U.S. Virgin Islands. The map layer was created by extr... Geological Survey (U.S.).
2006. Rawson, Peg. This point shapefile depicts major dams in the United States, including Puerto Rico and the U.S. Virgin Islands. The map layer was created by extra... United States. Bureau of Transportation Statistics.
1999. Geological Survey (U.S.). This line shapefile portrays the major roads in the United States, Puerto Rico, and the U.S. Virgin Islands. The file was produced by joining the i... Geological Survey (U.S.).
2003. Geological Survey (U.S.) Minerals Information Team. This point shapefile represents ferrous metal processing plants in the United States. The data represent commodities covered by the Minerals Inform... National Atlas of the United States.
2004. National Atlas of the United States. This polygon shapefile portrays county level data for the fiscal-year-2004 National Fire Plan - Hazardous Fuels Reduction Program. The purpose of t... National Atlas of the United States.